PV screw corrosion protection process comparison:
1. Stainless Steel Material
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304 stainless: Good corrosion resistance, general environment
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316 stainless: Contains molybdenum, salt spray resistant
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Advantages: No surface treatment needed, aesthetic
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Disadvantages: Higher cost, slightly lower strength than carbon steel
2. Hot-dip Galvanizing
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Zinc coating: 60-80μm
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Salt spray test: 500-1000 hours
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Advantages: Good corrosion protection, moderate cost
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Disadvantages: Thick coating affects dimensional accuracy
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Application: Large ground stations
3. Dacromet Coating
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Coating thickness: 8-12μm
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Salt spray test: 600-1200 hours
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Advantages: High dimensional accuracy, no hydrogen embrittlement
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Disadvantages: Higher cost, single color (silver gray)
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Application: Precision connections
4. Electro-galvanizing
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Zinc coating: 5-15μm
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Salt spray test: 72-200 hours
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Advantages: Low cost, bright appearance
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Disadvantages: Moderate corrosion protection
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Application: Indoor or dry environments
Selection Guide:
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Coastal areas: 316 stainless or hot-dip galvanized
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General outdoor: 304 stainless or Dacromet
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Large stations: Hot-dip galvanized (cost advantage)
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Precision connections: Dacromet (dimensional accuracy)
